A utensil having sensors in the handle is disclosed by DE102011080246. In that utensil, infrared sensors are arranged for determining the position of the utensil on the hob by a plurality of fixed infrared beacons provided on the cooking hob.
Other “intelligent” kitchen utensils are known in the art. Such known utensils include lance-shaped thermometers that may be inserted into foodstuff, such as meat and fish, both for pan cooking and for convection ovens. Such lance thermometers come either in the form of simple electromechanical devices or electronic ones, and in some cases they are equipped with wireless communication means with the appliance in order to perform an automatic regulation of the energy sources with the object of reaching target temperatures.
Temperature probes of the type described in EP1239703B1 combine temperature information with other physical parameters related to food state, such as conductivity, humidity, and vibration.
One drawback of such temperature probes is that they are not able to determine the actual action being performed with the utensil itself, thus resulting in the inability to relate the sensed quantities to the use scenario being performed by the user (i.e., the use context). For instance, the information returned by a temperature sensor has a different meaning if captured with the utensil being inserted stationary inside a casserole versus the case when the utensil is being used to stir a risotto. Even if not manipulated (i.e., zero acceleration), the information read by the sensor is interpreted differently if the probe is dipped vertically inside a pot compared to inserted horizontally inside a roast. In other words, the knowledge of the position, displacement, and acceleration is fundamental for the correct interpretation of the sensor readings.
DE3119496 and U.S. Pat. No. 6,753,027B1 try to obviate those limitations by adopting multiple temperature measuring points along the part of the probe which is to be inserted into the food. Although the plurality of temperature sensors mitigates the problem of detecting the very core temperature of the food, they all have the drawback of being unable to detect the actual position of the probe with respect to the food, resulting in largely varying results caused by the degree of expertise of the user or cook in correctly placing the probe. To partially obviate to that limitation, WO2012149997A1 proposes a method to assess probe tip orientation with respect to food surface, based on the relationship among the different temperatures monitored along the different measuring points positioned on the probe itself. However this temperature-based determination of the probe inclination might be highly disturbed by food anisotropy (i.e., non-uniformity) and spatial gradient in the heat application sources.
The activity of cooking food items with cooking hobs entails a high degree of attention from the cook to manually regulate the burner's power output in accordance to the recipe requirements. Such regulation generally occurs based on a cook's sensorial perception (visual, olfactory, texture), which is often weakly related with actual food state. Although professional and experienced cooks have developed great skill in inferring the actual cooking state from the aforementioned sensorial inputs, average cooks often struggle with the correct interpretation of such sensorial inputs, thus resulting in poorly prepared meals.